public class Example4_7 {
	public static void main(String args[]) {
	Battery nanfu = new Battery(100);       //创建电池对象
    System.out.println("南孚电池的储电量是:"+nanfu.electricityAmount);
    Radio radio = new Radio();             //创建收音机对象
    System.out.println("收音机开始使用南孚电池");
    radio.openRadio(nanfu);                //打开收音机
    System.out.println("目前南孚电池的储电量是:"+nanfu.electricityAmount);
    }
}